The present invention relates to a power receiving and transforming system and, more particularly, to a power receiving and transforming system of two-circuit power reception, two-bank type for distributing electric energy to feeders by way of a plurality of metal-enclosed switchgear.
Due to the cost of land, a power receiving and transforming system has been improved in various ways to decrease an installation space. More particularly, a gas insulated switchgear (hereinafter GIS) has been proposed in which an excellent insulation property of SF.sub.6 gas is effectively utilized. Since the installation space can be largely reduced and the reliability can be also improved in comparison with a conventional air-insulation transforming system, most of the power receiving and transforming systems include GISs.
GISs have been further reduced in size as a result of various technical researches. For example, in a system of two-circuit power reception, two-bank type which is a standard skeleton for a large customer, as disclosed in Japanese Patent Unexamined Publication No. 1-303002, it is possible to decrease a GIS in size so as to be transportable as a fully assembled apparatus. Moreover, a transformer (hereinafter TR) and a metal-enclosed switchgear (hereinafter MCS) have been each reduced in size.
As shown in FIG. 11, a width WG and a length LG of a GIS 40 which is transportable as a fully assembled apparatus are determined by dimensions of a trailer. In general, the width WG is about 6000 mm, and the length LG is about 3200 mm. Also, FIG. 11 schematically shows TR's 2a, 2b of which body has dimensions dT.times.lT except for cooling devices 21a, 21b. The length of the TRs 2a, 2b is perpendicular to the widthwise direction of the GIS 40. Connection buses of the TRs 2a, 2b are respectively connected to the GIS 40 through connecting portions 13a, 13b. Consequently, a transportation or installation length LT of the TR 2a, 2b is relatively large due to the longitudinal dimension lT of the bodies. Further, a plurality of MCS's 3a, 3b, which are connected to the two TRs 2a, 2b through connecting portions 22a, 22b, have MCS units juxtaposed along the widthwise direction, so that the MCSs have a juxtaposition width WM and a length LM.
In the power receiving and transforming system of this structure, a plurality of MCSs 3a, 3b are located to have their units juxtaposed in one line, so that an area of a site for installing the system is determined by the width WM of the MCSs 3a, 3b. Therefore, in spite of the size reduction of the GIS 40, a relatively large site is necessary, and it is difficult to utilize the land effectively. This disadvantage is induced because the developments of component apparatus for the purpose of the size reduction have been individually conducted and size reduction of the system as a whole has never been tried.